503 Service Unavailable on Shared Hosting: Causes and Fixes
Tested in a ShoHost sandbox on 12 October 2026: Apache 2.4.68 and PHP 8.4 on Debian, captured with headless Chrome. We sent PHP requests to a PHP-FPM socket that wasn’t running, which is what happens when a site’s PHP pool crashes or is full. Every screenshot below is from that sandbox, not from a customer…